CTX-M enzymes, the plasmid-mediated cefotaximases, constitute a rapidly growing family of extended-spectrum β-lactamases (ESBLs) with significant clinical impact. CTX-Ms are found in at least 26 bacterial species, particularly in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. At least 109 members in CTX-M family are identified and can be divided into seven clusters based on thei...

background & objectives:extended-spectrum-b-lactamase (esbl)-producing strains of klebsiella pneumoniaare an important cause of many serious infections in hospitalized and nonhospitalized patients and delayed treatment of these infections in crease chance of death in patients. this study was performed to determine the prevalence of esbl-producing k. pneumonia and to evaluate the frequency o...

Aeromonas species, aquatic Gram-negative bacilli, distributed globally and ubiquitously in the natural environment, may be implicated in a variety of human diseases. They can produce various β-lactamases which confer resistance to a broad spectrum of β-lactams, and therefore in vitro susceptibility testing must be used to guide antimicrobial therapy. However, conventional in vitro susceptibilit...

The accurate detection of carbapenemase-producing organisms is a major challenge for clinical laboratories. The Carba NP test is highly accurate but inconvenient, as it requires frequent preparation of fresh imipenem solution. The current study was designed to compare the Carba NP test to two alternative tests for accuracy and convenience. These were a modified Carba NP test that utilized intra...

The main aim of this study was to understand the relationship between the drug-resistant characteristics of Klebsiella pneumoniae and CTX-M-type extended spectrum β-lactamases (ESBLs), and to detect the distributions of CTX-M-type ESBLs in clinically isolated strains. CTX-M ESBL genes isolated from the clinical samples were amplified by polymerase chain reaction and identified by sequence analy...

Antimicrobial treatment of Klebsiella pneumoniae infections can be complicated by the existence of multiply-antibiotic resistant (multiresistant) strains carrying plasmids coding for extended-spectrum β-lactamases (ESBLs), AmpC-type β-lactamases (ACTBLs), or aminoglycoside-modifying enzymes. This situation has become an increasingly serious problem worldwide with incidences ranging from 5% in t...

Background and Objective: Beta-lactamases are the most important factors in the resistance to beta-lactam antibiotics among gram-negative bacteria, especially Klebsiella pneumoniae. Nowadays, the prevalence of infections caused by extended-spectrum β-lactamases (ESBLs)-producing K. pneumoniae is increasing, as one of the emerging health problems throughout the world. This study aimed to investi...

Klebsiella pneumoniae strains producing extended-spectrum β-lactamases (ESBL) exhibit resistance to antibiotic classes. The production of ESBLs (TEM-1, TEM-2, SHV-1, OXA-1) results in resistance to ampicillin, ticarcillin, piperacillin and cephalosporins. High levels of β-lactamases leads to development of resistance to β-lactamase inhibitors. The present study deals with characterizing antimic...